Eheim



March 22, 1955 EHEM 2,704,638

WINDER HEAD ON SPOOLERS FOR CONICAL CROSS-WOUND BOBBINS Filed April 14, 1953 IN vz vrak WA A. 7'R EMF/M United States Patent WINDER HEAD ON SPOOLERS FOR CONICAL CROSS-WOUND BOBBINS Walter Eheim, Zurich, Switzerland Application April 14, 1953, Serial No. 348,755

Claims priority, application Switzerland April 16, 1952 2 Claims. (Cl. 242-465) This invention relates to improved mandrels for spoolers of winder heads.

In the textile industry, spoolers are known for producing conical cross-wound packages which afford the advantage that the thread may be drawn off therefrom in an axial direction without excessive ballooning.

Such spoolers comprise a winder head having a hollowcone mandrel which serves as package-and-core holder or mount and, in known constructions, has longitudinal slots extending from the cone base to form resilient leaves intended to clampedly engage a package core slidably mounted on said mandrel. With a view toward making the inertia of the rotary members as small as possible, the conical mandrels up to the present have been made of light metal which, however, has the disadvantage that it is rather brittle. In operation, therefore, it was very often found that the resilient leaves of the conical mandrels did not stand up under the arising bending stresses and failed.

The main object of my present invention is to overcome the said disadvantage by making the hollow-cone mandrel of a resilient plastic. The mandrel preferably is made of a thermoplastic material possessing the requisite resilience, breaking strength and resistance to abra- S1011.

Apart from eliminating the deficiencies described above, a mandrel made of plastic has the further advantages of smaller inertia and lower manufacturing costs.

One form of my present invention is shown in the accompanying drawing, in which:

Fig. 1 shows the winder head in side view,

Fig. 2 is a top plan view of a portion of Fig. 1, and

Fig. 3 shows a portion of the cone mandrel in section on the line III-III of Fig. 2.

The winder head illustrated comprises a package-andcore holder mandrel which has the shape of a hollowcone and is supported on a shaft 11 by its smaller end. The shaft 11 is rotatably mounted on a bracket 12 by means of ball bearings housed inside the mandrel 10, as known in prior art. The mandrel 10 on its circumference is provided with a plurality of equidistant longitudinal slots 13 which extend from the cone base and form leaves14 on the mandrel 10. The said leaves are resilient and may be slightly spread outwardly, in a manner known per se, by means of an element, not shown in the drawing, which is disposed inside the hollow cone, in order to clampedly engage a bobbin core (not shown) slidably mounted on the mandrel 10. For the purpose of attaining a positive engagement of the bobbin core on the holder or mandrel 10, the latter is provided with a plurality of circumferential ribs 15 which are of sawtooth-shape in profile and extend over a portion addition of softeners or plasticizers being possible.

of the free end of the leaves 14. The cone base, furthermore, is provided with an outwardly flared circumferential rim 16 which serves as stop for the bobbin core to be mounted on the mandrel 10.

The novelty of the winder head described is that the mandrel 10 is made of an elastically resilient plastic which enables the leaves 14 to resiliently yield towards and away from the shaft 11 and affords a high breaking strength when subjected to continued bending stresses. As a material possessing these properties, preferably a thermoplastic material may be used, which affords the further advantage of high resistance against abrasion, so that practically no wear of the mandrel or holder 10 is to be feared.

The material of the mandrel 10 may consist, partly or entirely, of a polyamide, polyaminochloride, polystyrene or of mixed polymerization. It, however, also could be made, partly or entirely, of cellulose acetate or cellu lose-acetate butyrate. In any case it is possible to make the mandrel 10 of a mixture of different plastics, the

The mandrel 10 suitably is formed by die casting.

The leaves 14 are stiffened on their free ends by longitudinal ribs 17 which also are engaged by the element for spreading the leaves 14. In order to obviate any warping when making the mandrel 10, local accumulations of material have to be avoided on the mandrel 10, in particular on its leaves 14. For such purpose, the longitudinal ribs 17 are disposed immediately adjacent the slots 13 and are of a thickness substantially equal to that of the hollow cone.

The winder head described has fully met the requirements of practical application. With suitable choice of the material, the leaves 14 may be spread far outwardly without risk of breaking, and they resume their initial poslitions under the action of the resilience of the materia While the preferred embodiment of the invention has been shown and herein described, it will be understood that the same is capable of embodiment without departure from the general scope and spirit of the invention as defined in the claims.

Having thus described the invention, what is claimed. as new and desired to be secured by Letters Patent, is:

1. In a winder head for spoolers for producing thereon conical cross-wound bobbins; a hollow cone which serves as package-and-core mandrel and provided with longitudinal slots extending from the base of said cone for the purpose of forming resilient leaves between said slots and adapted to clampedly engage a bobbin core slidably mounted thereon, said mandrel leaves being stiffened on their free ends by longitudinal ribs disposed on the inside of said leaves, said mandrel being made of resilient plastic material.

2. In a winder head according to claim 1, wherein said longitudinal ribs are of substantially the same thickness as said hollow cone mandrel.

References Cited in the file of this patent UNITED STATES PATENTS 678,507 McKean July 16, 1901 690,493 Wardwell Jan. 7, 1902 2,571,321 Wettley Oct. 16, 1951 2,585,999 Bunch Feb. 19, 1952 2,615,644 Enz Oct. 28, 1952 

